/*
* Copyright 2000-2016 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.data;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;
import com.vaadin.data.HasValue.ValueChangeEvent;
import com.vaadin.data.util.converter.Converter;
import com.vaadin.data.util.converter.StringToIntegerConverter;
import com.vaadin.data.util.converter.ValueContext;
import com.vaadin.event.EventRouter;
import com.vaadin.server.ErrorMessage;
import com.vaadin.server.SerializableBiConsumer;
import com.vaadin.server.SerializableFunction;
import com.vaadin.server.SerializablePredicate;
import com.vaadin.server.UserError;
import com.vaadin.shared.Registration;
import com.vaadin.ui.AbstractComponent;
import com.vaadin.ui.Component;
import com.vaadin.ui.Label;
import com.vaadin.ui.UI;
/**
* Connects one or more {@code Field} components to properties of a backing data
* type such as a bean type. With a binder, input components can be grouped
* together into forms to easily create and update business objects with little
* explicit logic needed to move data between the UI and the data layers of the
* application.
*
* A binder is a collection of bindings, each representing the mapping of
* a single field, through converters and validators, to a backing property.
*
* A binder instance can be bound to a single bean instance at a time, but can
* be rebound as needed. This allows usage patterns like a master-details
* view, where a select component is used to pick the bean to edit.
*
* Bean level validators can be added using the
* {@link #withValidator(Validator)} method and will be run on the bound bean
* once it has been updated from the values of the bound fields. Bean level
* validators are also run as part of {@link #writeBean(Object)} and
* {@link #writeBeanIfValid(Object)} if all field level validators pass.
*
* Note: For bean level validators, the bean must be updated before the
* validators are run. If a bean level validator fails in
* {@link #writeBean(Object)} or {@link #writeBeanIfValid(Object)}, the bean
* will be reverted to the previous state before returning from the method. You
* should ensure that the getters/setters in the bean do not have side effects.
*
* Unless otherwise specified, {@code Binder} method arguments cannot be null.
*
* @author Vaadin Ltd.
*
* @param
* the bean type
*
* @see BindingBuilder
* @see Binding
* @see HasValue
*
* @since 8.0
*/
public class Binder implements Serializable {
/**
* Represents the binding between a field and a data property.
*
* @param
* the bean type
* @param
* the target data type of the binding, matches the field type
* unless a converter has been set
*
* @see Binder#forField(HasValue)
*/
public interface Binding extends Serializable {
/**
* Gets the field the binding uses.
*
* @return the field for the binding
*/
public HasValue getField();
/**
* Validates the field value and returns a {@code ValidationStatus}
* instance representing the outcome of the validation.
*
* @see Binder#validate()
* @see Validator#apply(Object)
*
* @return the validation result.
*/
public ValidationStatus validate();
}
/**
* Creates a binding between a field and a data property.
*
* @param
* the bean type
* @param
* the target data type of the binding, matches the field type
* until a converter has been set
*
* @see Binder#forField(HasValue)
*/
public interface BindingBuilder extends Serializable {
/**
* Completes this binding using the given getter and setter functions
* representing a backing bean property. The functions are used to
* update the field value from the property and to store the field value
* to the property, respectively.
*
* When a bean is bound with {@link Binder#setBean(BEAN)}, the field
* value is set to the return value of the given getter. The property
* value is then updated via the given setter whenever the field value
* changes. The setter may be null; in that case the property value is
* never updated and the binding is said to be read-only.
*
* If the Binder is already bound to some bean, the newly bound field is
* associated with the corresponding bean property as described above.
*
* The getter and setter can be arbitrary functions, for instance
* implementing user-defined conversion or validation. However, in the
* most basic use case you can simply pass a pair of method references
* to this method as follows:
*
*
* class Person {
* public String getName() { ... }
* public void setName(String name) { ... }
* }
*
* TextField nameField = new TextField();
* binder.forField(nameField).bind(Person::getName, Person::setName);
*
*
* @param getter
* the function to get the value of the property to the
* field, not null
* @param setter
* the function to write the field value to the property or
* null if read-only
* @return the newly created binding
* @throws IllegalStateException
* if {@code bind} has already been called on this binding
*/
public Binding bind(
SerializableFunction getter,
com.vaadin.server.SerializableBiConsumer setter);
/**
* Adds a validator to this binding. Validators are applied, in
* registration order, when the field value is written to the backing
* property. If any validator returns a failure, the property value is
* not updated.
*
* @see #withValidator(SerializablePredicate, String)
* @see #withValidator(SerializablePredicate, ErrorMessageProvider)
*
* @param validator
* the validator to add, not null
* @return this binding, for chaining
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public BindingBuilder withValidator(
Validator validator);
/**
* A convenience method to add a validator to this binding using the
* {@link Validator#from(SerializablePredicate, String)} factory method.
*
* Validators are applied, in registration order, when the field value
* is written to the backing property. If any validator returns a
* failure, the property value is not updated.
*
* @see #withValidator(Validator)
* @see #withValidator(SerializablePredicate, ErrorMessageProvider)
* @see Validator#from(SerializablePredicate, String)
*
* @param predicate
* the predicate performing validation, not null
* @param message
* the error message to report in case validation failure
* @return this binding, for chaining
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public default BindingBuilder withValidator(
SerializablePredicate predicate,
String message) {
return withValidator(Validator.from(predicate, message));
}
/**
* A convenience method to add a validator to this binding using the
* {@link Validator#from(SerializablePredicate, ErrorMessageProvider)}
* factory method.
*
* Validators are applied, in registration order, when the field value
* is written to the backing property. If any validator returns a
* failure, the property value is not updated.
*
* @see #withValidator(Validator)
* @see #withValidator(SerializablePredicate, String)
* @see Validator#from(SerializablePredicate, ErrorMessageProvider)
*
* @param predicate
* the predicate performing validation, not null
* @param errorMessageProvider
* the provider to generate error messages, not null
* @return this binding, for chaining
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public default BindingBuilder withValidator(
SerializablePredicate predicate,
ErrorMessageProvider errorMessageProvider) {
return withValidator(
Validator.from(predicate, errorMessageProvider));
}
/**
* Maps the binding to another data type using the given
* {@link Converter}.
*
* A converter is capable of converting between a presentation type,
* which must match the current target data type of the binding, and a
* model type, which can be any data type and becomes the new target
* type of the binding. When invoking
* {@link #bind(SerializableFunction, SerializableBiConsumer)}, the
* target type of the binding must match the getter/setter types.
*
* For instance, a {@code TextField} can be bound to an integer-typed
* property using an appropriate converter such as a
* {@link StringToIntegerConverter}.
*
* @param
* the type to convert to
* @param converter
* the converter to use, not null
* @return a new binding with the appropriate type
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public BindingBuilder withConverter(
Converter converter);
/**
* Maps the binding to another data type using the mapping functions and
* a possible exception as the error message.
*
* The mapping functions are used to convert between a presentation
* type, which must match the current target data type of the binding,
* and a model type, which can be any data type and becomes the new
* target type of the binding. When invoking
* {@link #bind(SerializableFunction, SerializableBiConsumer)}, the
* target type of the binding must match the getter/setter types.
*
* For instance, a {@code TextField} can be bound to an integer-typed
* property using appropriate functions such as:
* withConverter(Integer::valueOf, String::valueOf);
*
* @param
* the type to convert to
* @param toModel
* the function which can convert from the old target type to
* the new target type
* @param toPresentation
* the function which can convert from the new target type to
* the old target type
* @return a new binding with the appropriate type
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public default BindingBuilder withConverter(
SerializableFunction toModel,
SerializableFunction toPresentation) {
return withConverter(Converter.from(toModel, toPresentation,
exception -> exception.getMessage()));
}
/**
* Maps the binding to another data type using the mapping functions and
* the given error error message if a value cannot be converted to the
* new target type.
*
* The mapping functions are used to convert between a presentation
* type, which must match the current target data type of the binding,
* and a model type, which can be any data type and becomes the new
* target type of the binding. When invoking
* {@link #bind(SerializableFunction, SerializableBiConsumer)}, the
* target type of the binding must match the getter/setter types.
*
* For instance, a {@code TextField} can be bound to an integer-typed
* property using appropriate functions such as:
* withConverter(Integer::valueOf, String::valueOf);
*
* @param
* the type to convert to
* @param toModel
* the function which can convert from the old target type to
* the new target type
* @param toPresentation
* the function which can convert from the new target type to
* the old target type
* @param errorMessage
* the error message to use if conversion using
* toModel fails
* @return a new binding with the appropriate type
* @throws IllegalStateException
* if {@code bind} has already been called
*/
public default BindingBuilder withConverter(
SerializableFunction toModel,
SerializableFunction toPresentation,
String errorMessage) {
return withConverter(Converter.from(toModel, toPresentation,
exception -> errorMessage));
}
/**
* Maps binding value {@code null} to given null representation and back
* to {@code null} when converting back to model value.
*
* @param nullRepresentation
* the value to use instead of {@code null}
* @return a new binding with null representation handling.
*/
public default BindingBuilder withNullRepresentation(
TARGET nullRepresentation) {
return withConverter(
fieldValue -> Objects.equals(fieldValue, nullRepresentation)
? null : fieldValue,
modelValue -> Objects.isNull(modelValue)
? nullRepresentation : modelValue);
}
/**
* Sets the given {@code label} to show an error message if validation
* fails.
*
* The validation state of each field is updated whenever the user
* modifies the value of that field. The validation state is by default
* shown using {@link AbstractComponent#setComponentError} which is used
* by the layout that the field is shown in. Most built-in layouts will
* show this as a red exclamation mark icon next to the component, so
* that hovering or tapping the icon shows a tooltip with the message
* text.
*
* This method allows to customize the way a binder displays error
* messages to get more flexibility than what
* {@link AbstractComponent#setComponentError} provides (it replaces the
* default behavior).
*
* This is just a shorthand for
* {@link #withValidationStatusHandler(ValidationStatusHandler)} method
* where the handler instance hides the {@code label} if there is no
* error and shows it with validation error message if validation fails.
* It means that it cannot be called after
* {@link #withValidationStatusHandler(ValidationStatusHandler)} method
* call or {@link #withValidationStatusHandler(ValidationStatusHandler)}
* after this method call.
*
* @see #withValidationStatusHandler(ValidationStatusHandler)
* @see AbstractComponent#setComponentError(ErrorMessage)
* @param label
* label to show validation status for the field
* @return this binding, for chaining
*/
public default BindingBuilder withStatusLabel(
Label label) {
return withValidationStatusHandler(status -> {
label.setValue(status.getMessage().orElse(""));
// Only show the label when validation has failed
label.setVisible(status.isError());
});
}
/**
* Sets a {@link ValidationStatusHandler} to track validation status
* changes.
*
* The validation state of each field is updated whenever the user
* modifies the value of that field. The validation state is by default
* shown using {@link AbstractComponent#setComponentError} which is used
* by the layout that the field is shown in. Most built-in layouts will
* show this as a red exclamation mark icon next to the component, so
* that hovering or tapping the icon shows a tooltip with the message
* text.
*
* This method allows to customize the way a binder displays error
* messages to get more flexibility than what
* {@link AbstractComponent#setComponentError} provides (it replaces the
* default behavior).
*
* The method may be called only once. It means there is no chain unlike
* {@link #withValidator(Validator)} or
* {@link #withConverter(Converter)}. Also it means that the shorthand
* method {@link #withStatusLabel(Label)} also may not be called after
* this method.
*
* @see #withStatusLabel(Label)
* @see AbstractComponent#setComponentError(ErrorMessage)
* @param handler
* status change handler
* @return this binding, for chaining
*/
public BindingBuilder withValidationStatusHandler(
ValidationStatusHandler handler);
/**
* Sets the field to be required. This means two things:
*
*
the required indicator is visible
*
the field value is validated for not being empty*
*
* For localizing the error message, use
* {@link #setRequired(SerializableFunction)}.
*
* *Value not being the equal to what {@link HasValue#getEmptyValue()}
* returns.
*
* @see #setRequired(SerializableFunction)
* @see HasValue#setRequiredIndicatorVisible(boolean)
* @see HasValue#isEmpty()
* @param errorMessage
* the error message to show for the invalid value
* @return this binding, for chaining
*/
public default BindingBuilder setRequired(
String errorMessage) {
return setRequired(context -> errorMessage);
}
/**
* Sets the field to be required. This means two things:
*
*
the required indicator is visible
*
the field value is validated for not being empty*
*
* *Value not being the equal to what {@link HasValue#getEmptyValue()}
* returns.
*
* @see HasValue#setRequiredIndicatorVisible(boolean)
* @see HasValue#isEmpty()
* @param errorMessageProvider
* the provider for localized validation error message
* @return this binding, for chaining
*/
public BindingBuilder setRequired(
ErrorMessageProvider errorMessageProvider);
}
/**
* An internal implementation of {@code BindingBuilder}.
*
* @param
* the bean type, must match the Binder bean type
* @param
* the value type of the field
* @param
* the target data type of the binding, matches the field type
* until a converter has been set
*/
protected static class BindingBuilderImpl
implements BindingBuilder {
private final Binder binder;
private final HasValue field;
private ValidationStatusHandler statusHandler;
private boolean isStatusHandlerChanged;
private boolean bound;
/**
* Contains all converters and validators chained together in the
* correct order.
*/
private Converter converterValidatorChain;
/**
* Creates a new binding builder associated with the given field.
* Initializes the builder with the given converter chain and status
* change handler.
*
* @param binder
* the binder this instance is connected to, not null
* @param field
* the field to bind, not null
* @param converterValidatorChain
* the converter/validator chain to use, not null
* @param statusHandler
* the handler to track validation status, not null
*/
protected BindingBuilderImpl(Binder binder,
HasValue field,
Converter converterValidatorChain,
ValidationStatusHandler statusHandler) {
this.field = field;
this.binder = binder;
this.converterValidatorChain = converterValidatorChain;
this.statusHandler = statusHandler;
}
@Override
public Binding bind(
SerializableFunction getter,
SerializableBiConsumer setter) {
checkUnbound();
Objects.requireNonNull(getter, "getter cannot be null");
BindingImpl binding = new BindingImpl<>(
this, getter, setter);
getBinder().bindings.add(binding);
if (getBinder().getBean() != null) {
binding.initFieldValue(getBinder().getBean());
}
getBinder().fireStatusChangeEvent(false);
bound = true;
return binding;
}
@Override
public BindingBuilder withValidator(
Validator validator) {
checkUnbound();
Objects.requireNonNull(validator, "validator cannot be null");
converterValidatorChain = converterValidatorChain
.chain(new ValidatorAsConverter<>(validator));
return this;
}
@Override
public BindingBuilder withConverter(
Converter converter) {
return withConverter(converter, true);
}
@Override
public BindingBuilder withValidationStatusHandler(
ValidationStatusHandler handler) {
checkUnbound();
Objects.requireNonNull(handler, "handler cannot be null");
if (isStatusHandlerChanged) {
throw new IllegalStateException(
"A " + ValidationStatusHandler.class.getSimpleName()
+ " has already been set");
}
isStatusHandlerChanged = true;
statusHandler = handler;
return this;
}
@Override
public BindingBuilder setRequired(
ErrorMessageProvider errorMessageProvider) {
checkUnbound();
field.setRequiredIndicatorVisible(true);
return withValidator(
value -> !Objects.equals(value, field.getEmptyValue()),
errorMessageProvider);
}
/**
* Implements {@link #withConverter(Converter)} method with additional
* possibility to disable (reset) default null representation converter.
*
* The method {@link #withConverter(Converter)} calls this method with
* {@code true} provided as the second argument value.
*
* @see #withConverter(Converter)
*
* @param converter
* the converter to use, not null
* @param resetNullRepresentation
* if {@code true} then default null representation will be
* deactivated (if not yet), otherwise it won't be removed
* @return a new binding with the appropriate type
* @param
* the type to convert to
* @throws IllegalStateException
* if {@code bind} has already been called
*/
protected BindingBuilder withConverter(
Converter converter,
boolean resetNullRepresentation) {
checkUnbound();
Objects.requireNonNull(converter, "converter cannot be null");
if (resetNullRepresentation) {
getBinder().initialConverters.get(field).setIdentity();
}
return getBinder().createBinding(field,
converterValidatorChain.chain(converter), statusHandler);
}
/**
* Returns the {@code Binder} connected to this {@code Binding}
* instance.
*
* @return the binder
*/
protected Binder getBinder() {
return binder;
}
/**
* Throws if this binding is already completed and cannot be modified
* anymore.
*
* @throws IllegalStateException
* if this binding is already bound
*/
protected void checkUnbound() {
if (bound) {
throw new IllegalStateException(
"cannot modify binding: already bound to a property");
}
}
}
/**
* An internal implementation of {@code Binding}.
*
* @param
* the bean type, must match the Binder bean type
* @param
* the value type of the field
* @param
* the target data type of the binding, matches the field type
* unless a converter has been set
*/
protected static class BindingImpl
implements Binding {
private final Binder binder;
private final HasValue field;
private final ValidationStatusHandler statusHandler;
private final SerializableFunction getter;
private final SerializableBiConsumer setter;
// Not final since we temporarily remove listener while changing values
private Registration onValueChange;
/**
* Contains all converters and validators chained together in the
* correct order.
*/
private final Converter converterValidatorChain;
public BindingImpl(BindingBuilderImpl builder,
SerializableFunction getter,
SerializableBiConsumer setter) {
this.binder = builder.getBinder();
this.field = builder.field;
this.statusHandler = builder.statusHandler;
converterValidatorChain = builder.converterValidatorChain;
onValueChange = getField()
.addValueChangeListener(this::handleFieldValueChange);
this.getter = getter;
this.setter = setter;
}
@Override
public HasValue getField() {
return field;
}
/**
* Finds an appropriate locale to be used in conversion and validation.
*
* @return the found locale, not null
*/
protected Locale findLocale() {
Locale l = null;
if (getField() instanceof Component) {
l = ((Component) getField()).getLocale();
}
if (l == null && UI.getCurrent() != null) {
l = UI.getCurrent().getLocale();
}
if (l == null) {
l = Locale.getDefault();
}
return l;
}
@Override
public ValidationStatus validate() {
ValidationStatus status = doValidation();
getBinder().getValidationStatusHandler()
.accept(new BinderValidationStatus<>(getBinder(),
Arrays.asList(status), Collections.emptyList()));
getBinder().fireStatusChangeEvent(status.isError());
return status;
}
/**
* Returns the field value run through all converters and validators,
* but doesn't pass the {@link ValidationStatus} to any status handler.
*
* @return the result of the conversion
*/
private Result doConversion() {
FIELDVALUE fieldValue = field.getValue();
return converterValidatorChain.convertToModel(fieldValue,
createValueContext());
}
private ValidationStatus toValidationStatus(
Result result) {
return new ValidationStatus<>(this,
result.isError()
? ValidationResult.error(result.getMessage().get())
: ValidationResult.ok());
}
/**
* Returns the field value run through all converters and validators,
* but doesn't pass the {@link ValidationStatus} to any status handler.
*
* @return the validation status
*/
private ValidationStatus doValidation() {
return toValidationStatus(doConversion());
}
/**
* Creates a value context from the current state of the binding and its
* field.
*
* @return the value context
*/
protected ValueContext createValueContext() {
if (field instanceof Component) {
return new ValueContext((Component) field);
}
return new ValueContext(findLocale());
}
/**
* Sets the field value by invoking the getter function on the given
* bean. The default listener attached to the field will be removed for
* the duration of this update.
*
* @param bean
* the bean to fetch the property value from
*/
private void initFieldValue(BEAN bean) {
assert bean != null;
assert onValueChange != null;
onValueChange.remove();
try {
getField().setValue(convertDataToFieldType(bean));
} finally {
onValueChange = getField()
.addValueChangeListener(this::handleFieldValueChange);
}
}
private FIELDVALUE convertDataToFieldType(BEAN bean) {
return converterValidatorChain.convertToPresentation(
getter.apply(bean), createValueContext());
}
/**
* Handles the value change triggered by the bound field.
*
* @param bean
* the new value
*/
private void handleFieldValueChange(
ValueChangeEvent event) {
getBinder().setHasChanges(true);
List binderValidationResults = Collections
.emptyList();
ValidationStatus fieldValidationStatus;
if (getBinder().getBean() != null) {
BEAN bean = getBinder().getBean();
fieldValidationStatus = writeFieldValue(bean);
if (!getBinder().bindings.stream()
.map(BindingImpl::doValidation)
.anyMatch(ValidationStatus::isError)) {
binderValidationResults = getBinder().validateBean(bean);
if (!binderValidationResults.stream()
.anyMatch(ValidationResult::isError)) {
getBinder().setHasChanges(false);
}
}
} else {
fieldValidationStatus = doValidation();
}
BinderValidationStatus status = new BinderValidationStatus<>(
getBinder(), Arrays.asList(fieldValidationStatus),
binderValidationResults);
getBinder().getValidationStatusHandler().accept(status);
getBinder().fireStatusChangeEvent(status.hasErrors());
}
/**
* Write the field value by invoking the setter function on the given
* bean, if the value passes all registered validators.
*
* @param bean
* the bean to set the property value to
*/
private ValidationStatus writeFieldValue(BEAN bean) {
assert bean != null;
Result result = doConversion();
if (setter != null) {
result.ifOk(value -> setter.accept(bean, value));
}
return toValidationStatus(result);
}
/**
* Returns the {@code Binder} connected to this {@code Binding}
* instance.
*
* @return the binder
*/
protected Binder getBinder() {
return binder;
}
private void notifyStatusHandler(ValidationStatus status) {
statusHandler.accept(status);
}
}
/**
* Wraps a validator as a converter.
*
* The type of the validator must be of the same type as this converter or a
* super type of it.
*
* @param
* the type of the converter
*/
private static class ValidatorAsConverter implements Converter {
private final Validator validator;
/**
* Creates a new converter wrapping the given validator.
*
* @param validator
* the validator to wrap
*/
public ValidatorAsConverter(Validator validator) {
this.validator = validator;
}
@Override
public Result convertToModel(T value, ValueContext context) {
ValidationResult validationResult = validator.apply(value, context);
if (validationResult.isError()) {
return Result.error(validationResult.getErrorMessage());
} else {
return Result.ok(value);
}
}
@Override
public T convertToPresentation(T value, ValueContext context) {
return value;
}
}
/**
* Converter decorator-strategy pattern to use initially provided "delegate"
* converter to execute its logic until the {@code setIdentity()} method is
* called. Once the method is called the class changes its behavior to the
* same as {@link Converter#identity()} behavior.
*/
private static class ConverterDelegate
implements Converter {
private Converter delegate;
private ConverterDelegate(Converter converter) {
delegate = converter;
}
@Override
public Result convertToModel(FIELDVALUE value,
ValueContext context) {
if (delegate == null) {
return Result.ok(value);
} else {
return delegate.convertToModel(value, context);
}
}
@Override
public FIELDVALUE convertToPresentation(FIELDVALUE value,
ValueContext context) {
if (delegate == null) {
return value;
} else {
return delegate.convertToPresentation(value, context);
}
}
void setIdentity() {
delegate = null;
}
}
private BEAN bean;
private final Set> bindings = new LinkedHashSet<>();
private final List> validators = new ArrayList<>();
private final Map, ConverterDelegate> initialConverters = new IdentityHashMap<>();
private EventRouter eventRouter;
private Label statusLabel;
private BinderValidationStatusHandler statusHandler;
private boolean hasChanges = false;
/**
* Returns the bean that has been bound with {@link #bind}, or null if a
* bean is not currently bound.
*
* @return the currently bound bean if any
*/
public BEAN getBean() {
return bean;
}
/**
* Creates a new binding for the given field. The returned builder may be
* further configured before invoking
* {@link BindingBuilder#bind(SerializableFunction, SerializableBiConsumer)}
* which completes the binding. Until {@code Binding.bind} is called, the
* binding has no effect.
*
* Note: Not all {@link HasValue} implementations support
* passing {@code null} as the value. For these the Binder will
* automatically change {@code null} to a null representation provided by
* {@link HasValue#getEmptyValue()}. This conversion is one-way only, if you
* want to have a two-way mapping back to {@code null}, use
* {@link BindingBuilder#withNullRepresentation(Object)}.
*
* @param
* the value type of the field
* @param field
* the field to be bound, not null
* @return the new binding
*
* @see #bind(HasValue, SerializableFunction, SerializableBiConsumer)
*/
public BindingBuilder forField(
HasValue field) {
Objects.requireNonNull(field, "field cannot be null");
// clear previous errors for this field and any bean level validation
clearError(field);
getStatusLabel().ifPresent(label -> label.setValue(""));
return createBinding(field, createNullRepresentationAdapter(field),
this::handleValidationStatus);
}
/**
* Binds a field to a bean property represented by the given getter and
* setter pair. The functions are used to update the field value from the
* property and to store the field value to the property, respectively.
*
* Use the {@link #forField(HasValue)} overload instead if you want to
* further configure the new binding.
*
* Note: Not all {@link HasValue} implementations support
* passing {@code null} as the value. For these the Binder will
* automatically change {@code null} to a null representation provided by
* {@link HasValue#getEmptyValue()}. This conversion is one-way only, if you
* want to have a two-way mapping back to {@code null}, use
* {@link #forField(HasValue)} and
* {@link Binding#withNullRepresentation(Object))}.
*
* When a bean is bound with {@link Binder#setBean(BEAN)}, the field value
* is set to the return value of the given getter. The property value is
* then updated via the given setter whenever the field value changes. The
* setter may be null; in that case the property value is never updated and
* the binding is said to be read-only.
*
* If the Binder is already bound to some bean, the newly bound field is
* associated with the corresponding bean property as described above.
*
* The getter and setter can be arbitrary functions, for instance
* implementing user-defined conversion or validation. However, in the most
* basic use case you can simply pass a pair of method references to this
* method as follows:
*
*
* class Person {
* public String getName() { ... }
* public void setName(String name) { ... }
* }
*
* TextField nameField = new TextField();
* binder.bind(nameField, Person::getName, Person::setName);
*
*
* @param
* the value type of the field
* @param field
* the field to bind, not null
* @param getter
* the function to get the value of the property to the field,
* not null
* @param setter
* the function to write the field value to the property or null
* if read-only
* @return the newly created binding
*/
public Binding bind(
HasValue field,
SerializableFunction getter,
SerializableBiConsumer setter) {
return forField(field).bind(getter, setter);
}
/**
* Binds the given bean to all the fields added to this Binder. A
* {@code null} value removes a currently bound bean.
*
* When a bean is bound, the field values are updated by invoking their
* corresponding getter functions. Any changes to field values are reflected
* back to their corresponding property values of the bean as long as the
* bean is bound.
*
* Any change made in the fields also runs validation for the field
* {@link Binding} and bean level validation for this binder (bean level
* validators are added using {@link Binder#withValidator(Validator)}.
*
* @see #readBean(Object)
* @see #writeBean(Object)
* @see #writeBeanIfValid(Object)
*
* @param bean
* the bean to edit, or {@code null} to remove a currently bound
* bean
*/
public void setBean(BEAN bean) {
if (bean == null) {
if (this.bean != null) {
doRemoveBean(true);
}
} else {
doRemoveBean(false);
this.bean = bean;
bindings.forEach(b -> b.initFieldValue(bean));
// if there has been field value change listeners that trigger
// validation, need to make sure the validation errors are cleared
getValidationStatusHandler().accept(
BinderValidationStatus.createUnresolvedStatus(this));
fireStatusChangeEvent(false);
}
}
/**
* Removes the currently set bean, if any. If there is no bound bean, does
* nothing.
*
* This is a shorthand for {@link #setBean(Object)} with {@code null} bean.
*/
public void removeBean() {
setBean(null);
}
/**
* Reads the bound property values from the given bean to the corresponding
* fields.
*
* The bean is not otherwise associated with this binder; in particular its
* property values are not bound to the field value changes. To achieve
* that, use {@link #setBean(BEAN)}.
*
* @see #setBean(Object)
* @see #writeBeanIfValid(Object)
* @see #writeBean(Object)
*
* @param bean
* the bean whose property values to read, not null
*/
public void readBean(BEAN bean) {
Objects.requireNonNull(bean, "bean cannot be null");
setHasChanges(false);
bindings.forEach(binding -> binding.initFieldValue(bean));
getValidationStatusHandler()
.accept(BinderValidationStatus.createUnresolvedStatus(this));
fireStatusChangeEvent(false);
}
/**
* Writes changes from the bound fields to the given bean if all validators
* (binding and bean level) pass.
*
* If any field binding validator fails, no values are written and a
* {@code ValidationException} is thrown.
*
* If all field level validators pass, the given bean is updated and bean
* level validators are run on the updated bean. If any bean level validator
* fails, the bean updates are reverted and a {@code ValidationException} is
* thrown.
*
* @see #writeBeanIfValid(Object)
* @see #readBean(Object)
* @see #setBean(Object)
*
* @param bean
* the object to which to write the field values, not
* {@code null}
* @throws ValidationException
* if some of the bound field values fail to validate
*/
public void writeBean(BEAN bean) throws ValidationException {
BinderValidationStatus status = doWriteIfValid(bean);
if (status.hasErrors()) {
throw new ValidationException(status.getFieldValidationErrors(),
status.getBeanValidationErrors());
}
}
/**
* Writes changes from the bound fields to the given bean if all validators
* (binding and bean level) pass.
*
* If any field binding validator fails, no values are written and
* false is returned.
*
* If all field level validators pass, the given bean is updated and bean
* level validators are run on the updated bean. If any bean level validator
* fails, the bean updates are reverted and false is returned.
*
* @see #writeBean(Object)
* @see #readBean(Object)
* @see #setBean(Object)
*
* @param bean
* the object to which to write the field values, not
* {@code null}
* @return {@code true} if there was no validation errors and the bean was
* updated, {@code false} otherwise
*/
public boolean writeBeanIfValid(BEAN bean) {
return doWriteIfValid(bean).isOk();
}
/**
* Writes the field values into the given bean if all field level validators
* pass. Runs bean level validators on the bean after writing.
*
* @param bean
* the bean to write field values into
* @return a list of field validation errors if such occur, otherwise a list
* of bean validation errors.
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
private BinderValidationStatus doWriteIfValid(BEAN bean) {
Objects.requireNonNull(bean, "bean cannot be null");
// First run fields level validation
List> bindingStatuses = validateBindings();
// If no validation errors then update bean
if (bindingStatuses.stream().filter(ValidationStatus::isError).findAny()
.isPresent()) {
fireStatusChangeEvent(true);
return new BinderValidationStatus<>(this, bindingStatuses,
Collections.emptyList());
}
// Store old bean values so we can restore them if validators fail
Map, Object> oldValues = new HashMap<>();
bindings.forEach(
binding -> oldValues.put(binding, binding.getter.apply(bean)));
bindings.forEach(binding -> binding.writeFieldValue(bean));
// Now run bean level validation against the updated bean
List binderResults = validateBean(bean);
boolean hasErrors = binderResults.stream()
.filter(ValidationResult::isError).findAny().isPresent();
if (hasErrors) {
// Bean validator failed, revert values
bindings.forEach((BindingImpl binding) -> binding.setter
.accept(bean, oldValues.get(binding)));
} else {
// Write successful, reset hasChanges to false
setHasChanges(false);
}
fireStatusChangeEvent(hasErrors);
return new BinderValidationStatus<>(this, bindingStatuses,
binderResults);
}
/**
* Adds an bean level validator.
*
* Bean level validators are applied on the bean instance after the bean is
* updated. If the validators fail, the bean instance is reverted to its
* previous state.
*
* @see #writeBean(Object)
* @see #writeBeanIfValid(Object)
* @see #withValidator(SerializablePredicate, String)
* @see #withValidator(SerializablePredicate, ErrorMessageProvider)
*
* @param validator
* the validator to add, not null
* @return this binder, for chaining
*/
public Binder withValidator(Validator validator) {
Objects.requireNonNull(validator, "validator cannot be null");
validators.add(validator);
return this;
}
/**
* A convenience method to add a validator to this binder using the
* {@link Validator#from(SerializablePredicate, String)} factory method.
*
* Bean level validators are applied on the bean instance after the bean is
* updated. If the validators fail, the bean instance is reverted to its
* previous state.
*
* @see #writeBean(Object)
* @see #writeBeanIfValid(Object)
* @see #withValidator(Validator)
* @see #withValidator(SerializablePredicate, ErrorMessageProvider)
*
* @param predicate
* the predicate performing validation, not null
* @param message
* the error message to report in case validation failure
* @return this binder, for chaining
*/
public Binder withValidator(SerializablePredicate predicate,
String message) {
return withValidator(Validator.from(predicate, message));
}
/**
* A convenience method to add a validator to this binder using the
* {@link Validator#from(SerializablePredicate, ErrorMessageProvider)}
* factory method.
*
* Bean level validators are applied on the bean instance after the bean is
* updated. If the validators fail, the bean instance is reverted to its
* previous state.
*
* @see #writeBean(Object)
* @see #writeBeanIfValid(Object)
* @see #withValidator(Validator)
* @see #withValidator(SerializablePredicate, String)
*
* @param predicate
* the predicate performing validation, not null
* @param errorMessageProvider
* the provider to generate error messages, not null
* @return this binder, for chaining
*/
public Binder withValidator(SerializablePredicate predicate,
ErrorMessageProvider errorMessageProvider) {
return withValidator(Validator.from(predicate, errorMessageProvider));
}
/**
* Validates the values of all bound fields and returns the validation
* status.
*
* If all field level validators pass, and {@link #setBean(Object)} has been
* used to bind to a bean, bean level validators are run for that bean. Bean
* level validators are ignored if there is no bound bean or if any field
* level validator fails.
*
*
* @return validation status for the binder
*/
public BinderValidationStatus validate() {
List> bindingStatuses = validateBindings();
BinderValidationStatus validationStatus;
if (bindingStatuses.stream().filter(ValidationStatus::isError).findAny()
.isPresent() || bean == null) {
validationStatus = new BinderValidationStatus<>(this,
bindingStatuses, Collections.emptyList());
} else {
validationStatus = new BinderValidationStatus<>(this,
bindingStatuses, validateBean(bean));
}
getValidationStatusHandler().accept(validationStatus);
fireStatusChangeEvent(validationStatus.hasErrors());
return validationStatus;
}
/**
* Validates the bindings and returns the result of the validation as a list
* of validation statuses.
*
* Does not run bean validators.
*
* @see #validateBean(Object)
*
* @return an immutable list of validation results for bindings
*/
private List> validateBindings() {
List> results = new ArrayList<>();
for (BindingImpl binding : bindings) {
results.add(binding.doValidation());
}
return results;
}
/**
* Validates the {@code bean} using validators added using
* {@link #withValidator(Validator)} and returns the result of the
* validation as a list of validation results.
*
*
* @see #withValidator(Validator)
*
* @param bean
* the bean to validate
* @return a list of validation errors or an empty list if validation
* succeeded
*/
private List validateBean(BEAN bean) {
Objects.requireNonNull(bean, "bean cannot be null");
List results = Collections
.unmodifiableList(validators.stream()
.map(validator -> validator.apply(bean,
new ValueContext()))
.collect(Collectors.toList()));
return results;
}
/**
* Sets the label to show the binder level validation errors not related to
* any specific field.
*
* Only the one validation error message is shown in this label at a time.
*
* This is a convenience method for
* {@link #setValidationStatusHandler(BinderStatusHandler)}, which means
* that this method cannot be used after the handler has been set. Also the
* handler cannot be set after this label has been set.
*
* @param statusLabel
* the status label to set
* @see #setValidationStatusHandler(BinderStatusHandler)
* @see BindingBuilder#withStatusLabel(Label)
*/
public void setStatusLabel(Label statusLabel) {
if (statusHandler != null) {
throw new IllegalStateException("Cannot set status label if a "
+ BinderValidationStatusHandler.class.getSimpleName()
+ " has already been set.");
}
this.statusLabel = statusLabel;
}
/**
* Gets the status label or an empty optional if none has been set.
*
* @return the optional status label
* @see #setStatusLabel(Label)
*/
public Optional